stm32/boardctrl: Adjust logic for running boot.py, main.py.
stm32/boardctrl: Adjust logic for running boot.py, main.py.

This new logic is equivalent to the old logic when the only possibilities
for reset_mode are NORMAL, SAFE_MODE and FILESYSTEM, which is the standard
case.  But the new logic also allows other reset_mode values (eg
BOOTLOADER) to run boot.py and main.py.

Signed-off-by: Damien George <99e6b749acbfbe2a596df99e91d24d6e1fdbee00@micropython.org>

pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython